Physicalities of polymer depend on the primary structure of the polymer chain. Therefore, in the composition of polymer, the reaction structure is designed by controlling the primary structure, such as molecular mass of polymer, molecular mass distribution, terminal structure, branch structure, or stereo structure. In recent years, in addition to such a minute control of the primary structure of polymer chain, there has been a trend of controlling the higher-order structure, such as stereoregularity of polymer compound by controlling assembly of polymer chain, such as grouping, self-assembly, crystallization, or phase separation.
As an example of the control of higher-order structure, there is a method of using crystal lattice with a specific molecular sequence of the reaction field for polymerization reaction. More specifically, when using a monomer molecule in crystallization state, since the monomer molecule itself has a reaction field of the polymerization reaction, a stereoregular polymer can be produced by proceeding polymerization reaction, with minimum movement of atoms or substituent, without changing position of center of gravity of each monomer molecule, or symmetry of the crystal in polymerization reaction. Such polymerization reaction is called topochemical polymerization.
The reaction path and reaction speed of topochemical polymerization depend on the crystal structure, that is an aggregation of monomer molecules, and the structure of the resultant polymer is determined depending on the molecular sequence of the crystal. Further, producing a polymer through the topochemical polymerization makes it possible to obtain a polymer without separation or purification, and also, since the process may be done without an organic solvent, it causes less environmental burden.
The foregoing method of proceeding the topochemical polymerization under the control of crystal lattice allows easy production of a stereoregular polymer. With this finding, there have been active studies of the topochemical polymerization with the reports about solid-phase polymerization of diacetylene (Document: H. Basser, Adv. Polym. Sci., 63, p. 1 (1984) etc.), and solid-phase polymerization of olefin (Document: M. Hasegawa, Adv. Phys. Org. Chem., 30, p. 117(1995) etc.) etc. Further, the inventors of the present invention have reported topochemical polymerization of diene monomer (Document: A. Matsumoto, T. Matsumura, S. Aoki, J. Chem. Soc., Chem. Commun., 1994, p. 1389).
The topochemical polymerization of diene monomer is explained below with an example, (Z, Z)-1,4-butadiene (hereinafter referred to as diene monomer) having substituents Y1 and Y2, shown in FIGS. 11 and 12. Note that, the substituents Y1 and Y2 are identical in this example.
As shown before the arrow of FIG. 11, the diene monomer has a crystal structure in which all the monomer molecules are aligned in the same direction in a column. More specifically, when viewing the plane (molecular plane) having the monomer molecules from one side of the lamination direction (column direction), all the monomer molecules in the molecular plane face the same direction. In other words, if assuming the molecule plane from one side of the lamination direction is the upper surface, all the molecular planes formed by the monomer molecules are stacked showing upper surfaces.
Therefore, when topochemical polymerization occurs in the diene monomer, the diene monomers of FIG. 11 are bonded together at the positions denoted by the broken line, thus producing a polymer. As shown in FIG. 11, the produced polymer (diene polymer) has repeating units:—CHY1—CH═CH—CHY2—. The repeating units of each diene polymer have the same configuration in the vicinity of the carbons to which the substituents Y1 and Y2 are bonded. The polymer having this stereoregularity is called a diisotactic.
On the other hand, there exists an isomer of the diisotactic stereoregular polymer, having disyndiotactic structure. As mentioned above, the physicalities of polymer depend on the stereoregularity. Therefore, the polymer having the stereoregularity of disyndiotactic differs in crystallization, mechanical characteristic, solvent resistance, thermostability etc. from the diisotactic polymer.
As shown after the arrow in FIG. 12, the disyndiotactic structure polymer has such a stereoregularity that the repeating units of —CHY1-CH═CH—CHY2- in the vicinity of the carbons to which the substituents Y1 and Y2 are bonded are alternately identical. More specifically, in the disyndiotactic polymer, the two adjacent units have different configurations in the vicinity of the carbons to which the substituents Y1 and Y2 are connected. In other words, the disyndiotactic polymer has repeating units in which two kinds of units with different configurations alternately appear with a certain cycle.
To obtain such a disyndiotactic polymer through topochemical polymerization, as shown before the arrow of FIG. 12, there has been a technique of stacking the molecular planes so that the upper surface and the rear surface alternately appear (Document: A. Matsumoto, S. Nagahama, T. Odani, J. Am. Chem. Soc., 122, p. 9109(2000); A. Matsumoto, Prog. React. Kinet. Mecha., 26, p. 59 (2001) etc). More specifically, when viewing the planes (molecular plane) having the monomer molecules from one side of the lamination direction, the direction of the monomer molecules in the molecular plane is alternately identical. Further, by causing topochemical polymerization in the monomer molecules having such a crystal structure, a diene monomer is produced at the position denoted by the broken line in the figure. Further, it is assumed that a disyndiotactic polymer is also obtained, as shown after the arrow in FIG. 12.
However, there has been no report of actual acquirement of disyndiotactic polymer through the topochemical polymerization. More specifically, in prior art, there has been a proposal of obtaining a disyndiotactic polymer by using the monomer molecules having the structure shown in FIG. 12, but there is no report of successful acquirement of disyndiotactic polymer by using the diene monomer molecules shown in FIG. 12, or through topochemical polymerization of the diene monomer molecules.
The present invention is made in view of the foregoing conventional problems, and an object is to find the diene monomer having the structure of FIG. 12, and to provide a stereoregular polymer with disyndiotactic characteristic through polymerization of the diene monomer. The present invention further provides the manufacturing methods thereof.